By William H. Sousa and George L. Kelling

This study evaluates explanations that have been advanced for the sharp decline in crime in New York City during the 1990s. The authors consider arguments that crime in New York City during the 1990s. The authors consider arguments that crime drops have been the result of socio-economic factors, such as an improving economy, falling numbers of teenaged males, and declining use of crack cocaine. They also consider the argument that police interventions—particularly the enforcement of laws against minor crimes, known as "broken windows" policing—played a major role.

New York: Manhattan Institute, Center for Civic Innovation, 2001. 32p.

By Priscillia Hunt, Jessica Saunders and John S. Hollywood

Even though there is a growing interest in predictive policing, to date there have been few, if any, formal evaluations of these programs. This report documents an assessment of a predictive policing effort in Shreveport, Louisiana, in 2012, which was conducted to evaluate the crime reduction effects of policing guided by statistical predictions. RAND researchers led multiple interviews and focus groups with the Shreveport Police Department throughout the course of the trial to document the implementation of the statistical predictive and prevention models. In addition to a basic assessment of the process, the report shows the crime impacts and costs directly attributable to the strategy. It is hoped that this will provide a fuller picture for police departments considering if and how a predictive policing strategy should be adopted.

There was no statistically significant change in property crime in the experimental districts that applied the predictive models compared with the control districts; therefore, overall, the intervention was deemed to have no effect. There are both statistical and substantive possibilities to explain this null effect. In addition, it is likely that the predictive policing program did not cost any more than the status quo.

Santa Monica, CA: RAND, 2014. 88p.

By Sungwoo Cho, Felipe Gonçalves, and Emily Weisburst

Do reductions in arrests increase crime? We study line-of-duty deaths of police officers, events that likely impact police behavior through increased fear but are unlikely to directly impact civilian behavior. Officer deaths cause significant short-term reductions in all arrest types, with the largest reductions in arrests for lower-level offenses. In contrast, we find no evidence of an increase in crime or a change in victim reporting through 911 calls. There is also no apparent threshold of arrest decline beyond which crime increases. Our findings suggest that enforcement activity can be reduced at the margin without incurring public safety costs.

Bonn, Germany: IZA – Institute of Labor Economics , 2021. 69p.

By Aaron Chalfin, David Mitre-Becerril and Morgan C. Williams, Jr.

In December 2014 and January 2015, police officers in New York City engaged in an organized slowdown of police work to protest the murder of two police officers who were targeted by a gunman while sitting in their patrol car. An influential 2017 article in Nature Human Behaviour studies the effect of the NYPD’s work slowdown on major crimes and concludes that the slowdown led to a significant improvement in public safety. Contrary to the remainder of the literature, the authors conclude that proactive policing can cause an increase in crime. We re-evaluate this claim and point out several fatal weaknesses in the authors’ analysis that call this finding into question. In particular, we note that there was considerable variation in the intensity of the slowdown across NYC communities and that the communities which experienced a more pronounced reduction in police proactivity did not experience the largest reductions in major crime. The authors’ analysis constitutes a quintessential example of an ecological fallacy in statistical reasoning, a logical miscalculation in which inferences from aggregated data are mistakenly applied to a more granular phenomenon. We raise several additional and equally compelling concerns regarding the tests presented in the paper and conclude that there is little evidence that the slowdown led to short-term changes in major crimes in either direction.

Department of Criminology, University of Pennsylvania. Department of Economics, Barnard College, Columbia University , 2021. 38p.

By Desmond Ang

Nearly a thousand officer-involved killings occur each year in the United States. This paper documents the large, racially-disparate impacts of these events on the educational and psychological well-being of Los Angeles public high school students. Exploiting hyperlocal variation in how close students live to a killing, I find that exposure to police violence leads to persistent decreases in GPA, increased incidence of emotional disturbance and lower rates of high school completion and college enrollment. These effects are driven entirely by black and Hispanic students in response to police killings of other minorities and are largest for incidents involving unarmed individuals.

Cambridge, MA: Harvard University, Kennedy School of Government, 2020. 81p.

The synthetic opioid crisis in North America has increased fatal overdose rates to unprecedented levels within a matter of a few years. It involves new technologies, a new source of supply (the chemical industry in China), and new forms of distribution (the internet and mail). These elements are perhaps even more difficult to suppress than other supply sources from foreign countries. This has led to an assumption that nothing can be learned from prior experience in trying to control drug markets.

This paper applies the insights of the “focused deterrence” approach developed by David Kennedy and Mark Kleiman, which involves using multiple levers to attain a specific policy goal. We conclude with some specific suggestions for local and national supply-control agencies— including the need to focus more on regulating rather than reducing markets to minimize harm, and to distinguish between markets not yet swamped by fentanyl or in transition and those where the drug is entrenched. Strategies appropriate in one context may not serve well in another.

Washington, DC: The Brookings Institution, 2020. 21p.

By Liz Ward, Sian Nicholas and Maria Willoughby

The Tackling Knives Action Programme (TKAP) ran initially from June 2008 until March 2009 and aimed to reduce teenage knife crime in ten police force areas in England and Wales. TKAP Phase II was then launched and the programme re-branded into the Tackling Knives and Serious Youth Violence Action Programme. Phase II ran from April 2009 to March 2010 in 16 police force areas (the original ten TKAP forces and six new areas)1 and aimed to reduce all serious violence involving 13- to 24-year-olds using a range of enforcement, education and prevention initiatives.

London: Home Office, 2011. 67p.

The Knife Crime Prevention Programme: Process Evaluation

By Grant Thornton UK LLP

The Knife Crime Prevention Programme (KCPP) is an intervention which aims to reduce the prevalence of knife carrying and use by young people. Young people are referred to the programme if they are aged between 10 and 17 and have been convicted of an offence where a knife or the threat of a knife is a feature. The programme is based on a national delivery framework, with flexibility for local adaptation. It was rolled out as part of the Home Office ‘Tackling Knives Action Programme’ (TKAP). This process evaluation was commissioned to:  provide a picture of the implementation and delivery of KCPP  explore participants’ knowledge, perceptions and attitudes to knife crime before and after the programme  explore staff attitudes to the programme.

London: Youth Justice Board for England and Wales 2013. 29p.

By Jeremy Schoenfelder

This research investigated the theft of copper, including scope, impacts, and countermeasures. The researchers completed a literature review to demonstrate a global perspective of the problem. They took a survey of other state departments of transportation, utility companies, and developers to determine both successful and unsuccessful techniques being used to deter copper theft and the impact copper theft had on other geographical regions and other industries. Additionally, the researchers conducted a site survey to gain knowledge of the specific issues impacting the Arizona Department of Transportation and what mitigation techniques it was implementing. During the time of the research it was found: 1. The Arizona Department of Transportation estimates that costs over the last two years have exceeded $500,000. 2. The Arizona Department of Transportation has been diligent in implementing and adapting various methods and/or techniques to prevent copper theft and apprehend culprits. Suggested mitigation techniques include: 1. Implement a collaborative effort among ADOT, the

contracted private investigation firm, and outside consultant(s) to review and amend efforts on a periodic basis to maximize effectiveness through a thinktank type of approach. 2. Implement a program that would monitor ongoing development of methods used by other organizations. 3. Make particular use of the Copper Keeper, a device that makes it difficult to pull wire through conduit by locking the wire in place through the tightening of a compression bolt.

Rockville, MD: MITC (Mid-Atlantic Innovative Technology Center), 2009. 51p.

By International Union of Railways

Metal theft is a big problem for railway networks as thieves target signalling cables, overhead power lines and even metal fences to sell it for scrap. Railway networks are designed to fail safe, which means that when a cable is cut, trains are brought to a stop. This protects passengers but can lead to long and frustrating delays while the problem is examined and fixed safely. This type of crime causes considerable disruptions and the costs that are associated with replacing and repairing the damage often massively exceed the value of the metal stolen. Loss of communication networks and damage to railway tracks also raise public safety concerns. A large proportion of railway networks funds come from the government, so these thefts are, ultimately, at the taxpayer’s expense. It is clear that the stolen metal is often transported across several borders and sold as scrap or for recycling far away from the actual scene of the crime. Thus, both national and international cooperation and collaboration initiatives are needed to raise awareness, provide expertise and best practice to allow the exchange of ideas between all parties involved. Therefore, only a structured and common approach can provide a wide and extended set of solutions.

Paris: International Union of Railways, 2013. 12p.

By U.S. Department of Energy. Office of Electricity Delivery and Energy Reliability

The U.S. Department of Energy (DOE), Office of Electricity Delivery and Energy Reliability (OE) monitors changes, threats, and risks to the energy infrastructure in the United States. As part of that responsibility, OE published research in 2007 on the theft of copper wire from electric utilities. Early in 2010 there was evidence of an increase in such thefts. Because of this increase, OE decided to update its 2007 assessment of copper wire thefts. 1 • Electric utilities have launched public awareness campaigns, offered rewards for information leading to the arrest and conviction of thieves, marked copper wire for easier recovery from scrap metal dealers, and collaborated with stakeholders. Copper wire theft continues today throughout the United States, but the magnitude of theft has been reduced considerably. The problem is not likely to cease as long as copper prices remain sufficiently attractive to would-be thieves. However, the combined efforts of electric utilities, lawmakers, scrap metal dealers, and local law enforcement have succeeded in reducing the problem and driving a wedge between copper price increases and comparable increases in copper theft. • Legislation to reduce copper theft has been introduced in every State and passed into law in all but five States as of August 2010. • Scrap metal dealers are cooperating with utilities and lawmakers, reporting suspected thefts, and disseminating information through ISRI’s Theft Alerts. • Local law enforcement has become more responsive to electric utilities facing copper theft and is collaborating to recover more stolen copper and arrest those responsible. Since the beginning of the 2004 spike in copper prices, copper theft and copper prices have been directly linked. Although this link continues today, the rate of thefts as a function of the upward pull of prices has been mitigated

Washington DC: The Department, 2010. 17p.

By Remone Govender

Cable theft could be currently considered as a significant problem, globally. The Eskom statistical figures indicate that cable theft creates a massive problem for service delivery and places a vast amount of pressure on its financial resources. Cable theft is highlighted on various different platforms within Eskom’s business operating units and while efforts for increased security and protection measures are in place, these measures appear to be inadequate to prevent it. This study investigated the extent of cable theft at Eskom and examined what actions Eskom and private security personnel should undertake to prevent it. This study further determined what action steps need be taken by Eskom’s internal security management team, and those responsible for the capturing of all relevant information related to it, in order to prevent any form of cable theft. This research has made four key contributions to the subject: (i) A new Eskom security structure was proposed, (ii) a newly designed Eskom training curriculum framework was designed for all private security personnel working at Eskom facilities, (iii) proposed changes to Eskom’s CURA system were made, and (iv) proposed changes were suggested for Eskom’s internal ENECC cable theft reporting system.

Kwadlangezwa, South Africa: University of Zululand, 2017. 355p.

By Daniel Mejía, Ervyn Norza, Santiago Tobón, and Martín Vanegas-Arias

We study the effects of broken windows policing on crime using geo-located crime and arrest reports for 80 Colombian cities. Broadly defined, broken windows policing consists of intensifying arrests -sometimes for minor offenses- to deter potential criminals. To estimate causal effects, we build grids of 200 × 200 meters over the urban perimeter of all cities and produce event studies to look at the effects of shocks in police activity in the periods to follow. We use spikes in the number of arrests with no warrant -which are more likely associated with unplanned police presence- as a proxy for shocks in broken windows policing. As expected, we observe an increase in crimes during the shock period, as each arrest implies at least one crime report. In the following periods, crimes decrease both in the place of the arrests and the surroundings. With many treated grids and many places exposed to spillovers, these effects add up. On aggregate, the crime reduction offsets the observed increase during the shock period. Direct effects are more immediate and precise at low crime grids, but beneficial spillovers seem more relevant at crime hot spots. The effects of broken windows policing circumscribe to cities with low or moderate organized crime, consistent with criminal organizations planning their activities more systematically than disorganized criminals.

Bogotá, Colombia: Universidad de los Andes–Facultad de Economía–CEDE, 2022. 34p.

By Juan Felipe García, Daniel Mejia, and Daniel Ortega .

The Plan Nacional de Vigilancia Comunitaria por Cuadrantes (PNVCC) is a new police patrolling program introduced in the eight major cities of Colombia in 2010 by the National Police. The strategy divides the largest cities into small geographical areas (cuadrantes), assigns six policemen to each, establishes a new patrolling protocol involving more community contact, and holds officers accountable for crime in their assigned area. The plan warranted a comprehensive training program for over 9,000 police officers aimed at improving interpersonal skills and implementation of the new patrolling protocols. By staggering the training schedule between three randomly chosen cohorts of police stations, we generate experimental variation in the exposure to training and in the effective implementation of the new police protocols induced by the Plan Cuadrantes. Comparing the 4 months immediately after training with the same months from the previous year, we find a significant reduction in several types of crime attributable to the training program, ranging from around .13 of a standard deviation for homicides to .18 of a standard deviation for brawls. These impacts are driven by very large effects in high crime areas and very small -or zero- effects in low crime neighborhoods. Once we take into account the high spatial concentration of crime, the estimated effects account for an overall reduction in the number of homicides of about 22%. We suggest that the training program affected crime by increasing the patrol police’s sense of accountability to the population and also possibly through higher police motivation. Large efficiency gains in public service provision may be attainable with relatively inexpensive interventions that bring public servants closer to their clients.

Bogotá, Colombia: Universidad de los Andes–Facultad de Economía–CEDE, 2013. 27p.

By Daniela Collazos, Eduardo García, Daniel Mejía, Daniel Ortega, and Santiago Tobón

Objectives: Test direct, spillover and aggregate effects of hot spots policing on crime in a high crime environment. Methods: We identified 967 hot spot street segments and randomly assigned 384 to a six-months increase in police patrols. To account for the complications resulting from a large experimental sample in a dense network of streets, we use randomization inference for hypothesis testing. We also use non-experimental streets to test for spillovers onto non-hot spots, and examine aggregate effects citywide. Results: Our results show an improvement in short term security perceptions and a reduction in car thefts, but no direct effects on other crimes or satisfaction with policing services. We see larger effects in the least secure places, especially for short term security perceptions, car thefts and assaults. We find no evidence of crime displacement but rather a decrease in car thefts in nearby hot spots and a decrease in assaults in nearby non-hot spots. We estimate that car thefts decreased citywide by about 11 percent. Conclusions: Our study highlights the importance of context when implementing hot spots policing. What seems to work in the U.S. or even in Bogotá is not as responsive in Medellín (and vice versa). Further research¿especially outside the U.S.¿is needed to understand the role of local crime patterns and police capacity on the effectiveness of hot spots policing.

Bogotá, Colombia: Universidad de los Andes–Facultad de Economía–CEDE, 2019. 44p.

Edited by Kempe Ronald Hope. Sr.

Much of the literature on police corruption and police reforms is dominated by case studies of societies classified as developed. However, under the influence of globalization, developing societies have become a focal point of scholarly interest and examination. Police Corruption and Police Reforms in Developing Societies provides critical analyses of the extent and nature of police corruption and misconduct in developing societies. It also examines police reform measures that have been implemented or are still necessary to control and mitigate the effects of police corruption in developing societies. This book offers a comprehensive and authoritative account of the causes and consequences of police corruption. It also relates lessons learned from police reform efforts that have been made in a wide cross section of developing societies spanning several continents.

Boca Raton, FL: CRC Press, 2016. 270p.

By Suat Çubukçu, Nusret M. Sahin, Erdal Tekin & Volkan Topalli

Police body-worn cameras (BWCs) have been the subject of much research on how the technology’s enhanced documentation of police/citizen interactions impact police behavior. Less attention has been paid to how BWC recordings affect the adjudication of citizen complaints against the police. We employ citizen complaint data from the Chicago Police Department and Civilian Office of Police Accountability filed between 2012-2020 to determine the extent to which BWC footage enhances the efficacy of evidence used to formulate a conclusion of responsibility, and whether bias against complainants based on race would subsequently be reduced. Accordingly, we exploit the staggered deployment of BWCs across 22 Chicago police districts over time to estimate the effect of BWCs on these outcomes. Our findings indicate that BWCs led to a significant decrease in the dismissal of investigations due to insufficient evidence ("not sustained") as well as a significant increase in disciplinary actions against police officers ("sustained" outcomes”) with sufficient evidence to sanction their misconduct. We further find that disparities in complaints across racial groups for the “unsustained” category fade away with the implementation of BWCs.

Cambridge, MA: National Bureau of Economic Research (NBER), 2021. 43p.

By D. Elaine Pressman

Risk factors for violent individuals have been used in risk assessment protocols for decades. Such tools and guides have been shown to be a valid and reliable way to assess risk of future violence. The risk assessment protocols currently available, however, have questionable relevance to violent extremists and terrorists because the factors used to assess risk do not relate to the background and motivations of this group of violent actors. The need was identified for a relevant tool for the population of violent ideologically motivated extremists. Approaches to risk assessment for violence are described in the document. These include unstructured clinical judgment, actuarial approaches and structured professional judgment (SPJ). Unstructured approaches have been criticized for not demonstrating high validity or good inter-rater reliability. Given the low base rate of violent extremists, it is difficult to create empirically based actuarial prediction instruments for violent extremism. The structured professional judgment approach (SPJ) has been used successfully with forensic populations and was considered appropriate for a tool to address risk assessment for the population of violent extremists. As current SPJ guides were found to be inadequate to address the specific historical and contextual features of violent extremists, a new SPJ guide was developed and is described in this document. The major goals of the project were to identify and compare the specific characteristics and factors of those who perpetrate “general” criminal violence and those who perpetrate ideologically motivated violence, to highlight the salient differences among the historical, contextual, attitudinal and protective risk factors of these types of criminal violence and to construct a new tool to assess the risk of violence in ideologically motivated extremists. ‘Political violence’, ‘radicalization’, ‘extremism’ and ‘terrorism’ were defined and elaborated in the document. The most significant risk factors relevant to violent extremism and terrorism were extracted from the literature and organized into a structured professional judgment (SPJ) protocol. Five categories were identified as risk factors and relevant items were identified for each category. These categories are modeled after other well-established SPJ tools but are item specific to violent extremism. The categories include attitude factors, contextual factors, historical factors, protective factors and demographic factors. A preliminary model for the assessment of de-radicalization and disengagement efficacy was proposed. The new SPJ protocol, Violent Extremist Risk Assessment or VERA is designed to be used with persons having a history of extremist violence or having been convicted of such offences. At this stage of development, the VERA is a conceptual “research” tool intended to generate debate and discussion.

Ottawa: Public Safety Canada, 2009. 44p.

By Kathryn M. Roberts

"Countering the radical Islamist narrative remains a high-profile priority of the United States in its ongoing efforts to counter domestic violent extremism. Since mid-2014, government officials have condemned the United States as unable to muster a satisfactory 'counter-narrative,' and emphasize the potentially devastating consequences of failure. Experts inside and outside the government describe the Islamic State as masters of the internet capable of reaching into the United States and turning its people into hate-filled, violently inspired terrorists at will. The idea that the United States must aggressively work to counter these messages domestically remains a given; but should it? The focus of this thesis is to examine current U.S. efforts in counter-messaging to determine why the United States believes it is failing, and what, if any, evidence supports the idea that a counter-narrative or counter-messaging should be part of domestic countering violent extremism (CVE) programs. Review of official documents found little basis to assess U.S. programs, as no meaningful published strategy, objectives, or performance data exist for current efforts. Moreover, the foundational assumptions underlying current programs suggest malalignment between what U.S. officials desire a counter-messaging effort to accomplish and what is realistically achievable. Based on these findings, it is recommended that domestic CVE programs eliminate counter-messaging from their portfolio."

Monterey, CA: Naval Postgraduate School, 2020. 119p.

National Academies of Sciences, Engineering, and Medicine.

Proactive policing, as a strategic approach used by police agencies to prevent crime, is a relatively new phenomenon in the United States. It developed from a crisis in confidence in policing that began to emerge in the 1960s because of social unrest, rising crime rates, and growing skepticism regarding the effectiveness of standard approaches to policing. In response, beginning in the 1980s and 1990s, innovative police practices and policies that took a more proactive approach began to develop. This report uses the term “proactive policing” to refer to all policing strategies that have as one of their goals the prevention or reduction of crime and disorder and that are not reactive in terms of focusing primarily on uncovering ongoing crime or on investigating or responding to crimes once they have occurred.

Proactive policing is distinguished from the everyday decisions of police officers to be proactive in specific situations and instead refers to a strategic decision by police agencies to use proactive police responses in a programmatic way to reduce crime. Today, proactive policing strategies are used widely in the United States. They are not isolated programs used by a select group of agencies but rather a set of ideas that have spread across the landscape of policing.

Proactive Policing reviews the evidence and discusses the data and methodological gaps on: (1) the effects of different forms of proactive policing on crime; (2) whether they are applied in a discriminatory manner; (3) whether they are being used in a legal fashion; and (4) community reaction. This report offers a comprehensive evaluation of proactive policing that includes not only its crime prevention impacts but also its broader implications for justice and U.S. communities.

Washington, DC: The National Academies Press. 2018. 408p. .